The need to interface a computer with a multitude of various external audio devices has increased dramatically with the advent of computer based audio products. These computer based audio products include a wide range of applications which can be further divided into several distinct categories, such as entertainment audio i.e., games and animation; educational audio, i.e., reading and writing tutors; training audio for use in commercial training programs; and, merchandising audio for presentations and sales.
The primary use of audio adapters to date occurs in the category of entertainment audio with computer game audio capturing the largest market share by far. Audio products in the computer based games market include SoundBlaster.TM. computer audio adapters, available from Creative Labs, Inc., of Milpitas, California. Other audio adapter cards are available from Mediavision of Fremont, Calif.
As the different types of connections to audio adapter cards, including interfaces for microphones, headphones, Musical Instrument Device Interface (MIDI) devices, CD-ROM drives, joysticks, etc., multiply in number, interface connections are constrained by the very limited mechanical space available for external device connectors on the back of IBM PC compatible computer adapter cards.
The industry has turned to external breakout cables to overcome this very limited space constraint. Generally, external breakout devices comprise one computer card which have an external rear connector of high pin density and low mechanical profile. A corresponding high pin density external connector attached to a multi-conductor cable plugs into the rear external computer audio adapter connector. The multi-conductor cable fans out the different electrical signals into several discrete and distinct industry standard connectors.
One very common computer game audio adapter card rear connector definition comprises a 15 pin D-Shell which is the mechanical and electrical standard for both MIDI and game joysticks. Although many manufacturers offer breakout cables for this connector, these breakout cables have several common shortcomings.
One shortcoming is the cost associated with the hardware needed to meet a published interface specification for the MIDI 1.0 specification and the IBM PC Game Port Specification.
Another shortcoming is the failure to comply with emissions regulations as prescribed by the Federal Communications Commission (FCC) Class B for electronic products used in the household. Many, if not most, computer game audio card manufacturers circumvent the requirement for the FCC Class B regulation. Computer game audio adapter manufacturers provide assembly schematics for their respective breakout cables directly to the consumer. The consumer is expected to assemble his own cable; because it is constructed by the consumer for personal use, the FCC Class regulation does not apply.
A further shortcoming of currently available breakout cables is the need for additional breakout connectors to support a dual joystick operation for use with compatible games having musical outputs.
Still another shortcoming of currently available breakout cables is the need for additional hardware to support not only a MIDI-In and a MIDI-Out interface, but also a MIDI-Thru interface.
The present invention is an improved breakout cable for interfacing to computer audio adapters which support both game port interfaces and MIDI connections.